Heretofore, the problem of a sheet mis-feed or a sheet double-feed in a collating run was particularly cumbersome and annoying. Most collators are not equipped to handle sheet feeding malfunctions in a convenient manner. When a malfunction is detected, some machines come to an "abrupt" halt. Now it should be understood, that the inertia in a rotary drum collator will cause the drum to rotate through several pockets before coming to a complete stop. In any event, the malfunctioning pocket will normally rotate under the discharge deck. This of course, makes the pocket inaccessible, and correction of the malfunction becomes very cumbersome. In such a case, the operator has to open a trap door in the machine housing, and crouch within the housing to reach the drum.
In other collators, detection of a malfunction goes undetected, and improperly collated stacks are measured at the end of the collation to see if they are the proper thickness. Naturally, if there is a mis-feed, the stack will be too thin, and will be rejected. Also, if there is a double-feed, the stack will be rejected for being too thick. The disadvantage of this system is, that a mis-feed and a double-feed appearing in the same stack, will indicate the proper thickness. This improperly collated stack would then be erroneously accepted as a fit stack.
In most of these prior collators, there was no way to easily correct the mistakes, either during or after the collation.
The present invention is concerned with providing a collator system that will allow easy access and correction of interim malfunctions, and proper detection of subsequent improperly collated stacks.